We often overestimate how much events (or purchases) will change our happiness

While we each may initially react quite differently to an event, we all have a built-in ability to detect and neutralize challenges to our happiness. This has been called our psychological immune system. Just as your body adjusts to getting into hot water, so your mind adjusts to change: the psychological reaction to changes in stimuli is analogous to the physiological reaction to changes in temperature. And your psychological immune system works a little like your physical immune system, which kicks in when faced with a threat, such as when someone nearby coughs or sneezes. This highlights the fact that many adaptation processes take place automatically and unconsciously; we simply get used to some changes without thinking about whether or not we really want to.

In one of the most interesting studies in this area, students were asked to predict how much worse their mood would be if they were rejected for a job: their average estimate was two points lower than their current mood on a ten-point scale. In sharp contrast, the actual effect of being rejected was only 0.4 points on the same ten-point scale, and that effect was fleeting: ten minutes after the rejection, their happiness levels had returned to normal. By the way, there was no real job offer - such is the fun that psychologists often have at their students’ expense.

Day one: the new phone has changed everything.

Week six: the camera is mostly photographing receipts.

Month nine: the battery percentage is mildly annoying.

The purchase did improve the daily routine. What vanished was the belief that improvement would remain emotionally loud. Attention moved on, novelty became background and ordinary life returned carrying messages, toothache, sunshine and the missing charger.

Our forecasts isolate the event. The rejected job fills the whole imagined screen; the actual rejection lands inside a day that also contains lunch, friends and another possibility. Students expected a large mood drop after a supposed rejection and recovered far faster than predicted. The mind has its own repair habits and rarely includes them in the forecast.

Pain is real while it lasts. Some circumstances alter wellbeing for years, and “people adapt” is a cruel answer to illness, poverty or danger. The narrower claim is still uncomfortable: we routinely exaggerate emotional duration at both ends. Heartbreak looks permanent. Luxury looks permanently thrilling.

This makes a strange equality. The mind helps us survive loss by reducing its volume, then performs the same trick on the purchase meant to transform us.

The final instalment can leave the account long after the object stopped attracting attention. Both facts appear on the same bank statement: the payment is still remarkable; the phone is not.